will be flying(am flying) to New York

[keannu]

Does only "will be flying" work here? What about "am flying"? Present progressive sometimes means the future, but it sounds awkward.

gz-22p
ex)By the time you arrive in Seoul, I will be flying(am flying) to New York.

 

[emsr2d2]

You need "I will be" there. The present continuous doesn't work as the future in that context.

By the time you arrive in Seoul, I will be on a plane to New York.
By the time you arrive in Seoul, I will be on my way to New York.
By the time you arrive in Seoul, I will be flying to New York.

Here is a way to use the present continuous but as you can see, it involves a totally different construction:

I am flying to New York on Sunday. I leave two hours before you arrive in Seoul.

 

[keannu]

It seems you should use the future tense in the main clause when there is a future adverb clause. Is that the reason?